Global Cortical Thinning Predicts Slower Forward and Backward Walking in Multiple Sclerosis

Area of Science:

• Neuroscience
• Neurology
• Radiology

Background:

• Gait impairment and falls are prevalent in multiple sclerosis (MS), significantly impacting patient mobility and quality of life.
• The underlying neural mechanisms of mobility decline in MS, particularly concerning diffuse cortical changes and complex gait tasks like backward walking, require further elucidation.

Purpose of the Study:

• To investigate the association between diffuse cortical thinning and walking speed (forward and backward) in individuals with MS.
• To determine if this association differs between individuals who fall and those who do not.

Main Methods:

• Forty-three individuals with MS underwent high-resolution structural MRI to assess cortical thickness and gray matter volume.
• Forward and backward Timed 25-Foot Walk tests were used to measure gait speed.
• Regression analyses with false discovery rate (FDR) correction were employed to examine relationships between neuroimaging measures and gait speed.

Main Results:

• A global cortical thinning component was significantly associated with slower forward and backward walking speeds in individuals with MS.
• Neither cortical thickness nor gray matter volume changes predicted gait speed in a region-specific manner.
• While fallers and nonfallers did not differ in gait speed or cortical thinning, exploratory analyses suggested a potentially stronger association between cortical thinning and gait in fallers, though not statistically significant after FDR correction.

Conclusions:

• Diffuse cortical thinning is a consistent neural correlate of gait slowing in multiple sclerosis.
• These findings highlight the importance of widespread cortical integrity for maintaining gait function in MS.
• Preliminary evidence suggests that the relationship between cortical thinning and gait may be more pronounced in individuals who have experienced recent falls.